The role of time in neural information processing

Lukas Groschner receives ERC Starting Grant to study temporal signal processing in the brain of the fruit fly

The brain of a fruit fly processes some visual signals within milliseconds, whereas others unfold over several minutes. Lukas Groschner of the Max Planck Institute for Biological Intelligence wants to decipher how the complex neuronal circuits in the fly brain operate on temporal signals over such a wide range. By bringing together biophysics and behavior, the researcher hopes to uncover the molecular intricacies and overarching mechanisms governing these processes. The project promises profound insights into the role of time in neural information processing. The European Research Council (ERC) is funding the project with 1.295 million euros.

The brain works on very different time scales. It processes temporal signals over at least nine orders of magnitude, ranging from fast electrical impulses that last only milliseconds up to circadian rhythms and beyond. While the processes that operate at both ends of this spectrum are well characterized, little is known about the intermediate times scale from hundreds of milliseconds up to minutes.

This time span is what Lukas Groschner from Alexander Borst's lab aims to investigate in his project ‘Temporal processing in Drosophila melanogaster’. The ERC is awarding this project with a starting grant of up to 1.295 million Euro. Such grants for individual emerging scientists are annually awarded to kickstart particularly promising and innovative research projects.

The project is based on the premise that nervous systems across species employ a common set of circuit architectures. Some of these enable the brain to delay, accumulate, and store signals over the time range from hundreds of milliseconds up to several minutes. “I aim to bridge biophysics and behavior”, says Groschner, “to describe these circuits in molecular detail and to search for general principles of how they compute”.

Using the fruit fly Drosophila as a model, the researcher aims to record and control the activity of identified nerve cells. The fly’s brain contains a comparatively small number of nerve cells and neural circuits of well-defined connectivity. This makes it the ideal ground to study the temporal mechanisms at play in a rigorous manner.

In detail, the project will address three main questions: The first is how neurons in the visual system orchestrate the delay of signals to compute the direction of visual motion. The second asks how visual information gets accumulated over time to inform behavior choices. And thirdly, Groschner asks “How does a brain construct a memory that is stable during times of immobility, but exquisitely malleable — sensitive to every step — during locomotion?” In summary, this project aims to shed light on fundamental principles that govern neural information processing and the role of time in it.